Species And Adaptations Flashcards
(19 cards)
What is evolution?
Change in the heritable trait within a population across generations. Change in the frequency of alleles in a population over time.
What are mutations?
Change in the sequence of an organism’s DNA.
What is gene flow?
Movement of genes from one population to another.
What is sexual reproduction?
New gene combination via random mating and meiotic division.
What is genetic drift?
Change due to random event or sampling of individuals.
What is the founder effect?
Few individuals start a new population with a different allele frequency than the original.
What defines a species?
Individuals with the potential to interbreed and produce fertile offspring in nature.
What is a population?
A localized group of organisms which belong to the same species.
What are the problems with the species definition?
Difficult to apply to fossils, asexual organisms don’t fit the criteria, horizontal gene transfer.
What is speciation?
Lineage-splitting event that produces two or more separate species.
What is geographic isolation?
Allopatric speciation where species occupy areas separated by time or space.
What is sympatric speciation?
Especially in plants and insects, species occupy the same place at the same time.
What is sympatric speciation by polyploidy?
A mechanism of speciation where polyploidy occurs.
What are ring species?
Population of a single species encircle an area of unsuitable habitat, leading to populations that cannot mate at the ends.
What is artificial selection?
Selective breeding as practiced by humans and domesticated plants and animals, e.g., dogs.
What is adaptation?
Trait that has been selected by natural selection and provides improved function.
What are the limits of adaptation?
Selection can only operate on the available genetic material and variation, morphology, physiology, and trade-offs.
What is exaptation?
Feature that performs a function but was not produced by natural selection for its current use.
What conditions must be met for adaptation?
Is it heritable? Is it functional? Does it increase fitness? How did it first evolve?
